Re: multivariate statistics (v25)

Te <nospam-abuse@bloodgate.com>

From: "Tels" <nospam-abuse@bloodgate.com>
To: "Simon Riggs" <simon@2ndquadrant.com>
Cc: "David Rowley" <david.rowley@2ndquadrant.com>, "Kyotaro HORIGUCHI" <horiguchi.kyotaro@lab.ntt.co.jp>, "Tomas Vondra" <tomas.vondra@2ndquadrant.com>, "Alvaro Herrera" <alvherre@2ndquadrant.com>, "David Fetter" <david@fetter.org>, "Dean Rasheed" <dean.a.rasheed@gmail.com>, "PostgreSQL-development" <pgsql-hackers@postgresql.org>
Date: 2017-04-05T19:19:04Z
Lists: pgsql-hackers
Moin,

On Wed, April 5, 2017 2:52 pm, Simon Riggs wrote:
> On 5 April 2017 at 10:47, David Rowley <david.rowley@2ndquadrant.com>
> wrote:
>
>>> I have some other comments.
>
> Me too.
>
>
> CREATE STATISTICS should take ShareUpdateExclusiveLock like ANALYZE.
>
> This change is in line with other changes in this and earlier
> releases. Comments and docs included.
>
> Patch ready to be applied directly barring objections.

I know I'm a bit late, but isn't the syntax backwards?

"CREATE STATISTICS s1 WITH (dependencies) ON (col_a, col_b) FROM table;"

These do it the other way round:

CREATE INDEX idx ON table (col_a);

AND:

   CREATE TABLE t (
     id INT  REFERENCES table_2 (col_b);
   );

Won't this be confusing and make things hard to remember?

Sorry for not asking earlier, I somehow missed this.

Regard,

Tels


Commits

  1. Collect and use multi-column dependency stats

  2. Implement SortSupport for macaddr data type

  3. Implement multivariate n-distinct coefficients

  4. Generate fmgr prototypes automatically